The Pea Shooter is the default weapon that never breaks, and is always available to the player. It does 18 base damage per shot, with a range of 6 tiles, and a firing rate of 3.33 shots per second. It cannot be upgraded in the Town, but can get small improvements via Permanent Upgrades at the Alien Ant.
It is a reliable, if weak, option, and mostly serves as an early-game option, or a fallback later in the game. It gains much less damage from increases to the Fighting Stat than the other Weapons, and its slow rate of fire, middling range, lack of piercing projectiles, and lack of any fancy frills make it a rather subpar choice for the later Biomes.